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  <title>Description of plus</title>
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<div><a href="../../index.html">Home</a> &gt;  <a href="../index.html">matgraph</a> &gt; <a href="index.html">@partition</a> &gt; plus.m</div>

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<h1>plus
</h1>

<h2><a name="_name"></a>PURPOSE <a href="#_top"><img alt="^" border="0" src="../../up.png"></a></h2>
<div class="box"><strong>plus --- p+q is the join of p and q</strong></div>

<h2><a name="_synopsis"></a>SYNOPSIS <a href="#_top"><img alt="^" border="0" src="../../up.png"></a></h2>
<div class="box"><strong>function r = plus(p,q) </strong></div>

<h2><a name="_description"></a>DESCRIPTION <a href="#_top"><img alt="^" border="0" src="../../up.png"></a></h2>
<div class="fragment"><pre class="comment"> plus --- p+q is the join of p and q</pre></div>

<!-- crossreference -->
<h2><a name="_cross"></a>CROSS-REFERENCE INFORMATION <a href="#_top"><img alt="^" border="0" src="../../up.png"></a></h2>
This function calls:
<ul style="list-style-image:url(../../matlabicon.gif)">
<li><a href="merge.html" class="code" title="function q = merge(p,x,y)">merge</a>	merge(p,x,y) --- form a partition from p by combining x and y's parts.</li><li><a href="nv.html" class="code" title="function n = nv(p)">nv</a>	nv(p) --- number of vertices (elements) of a partition</li></ul>
This function is called by:
<ul style="list-style-image:url(../../matlabicon.gif)">
</ul>
<!-- crossreference -->


<h2><a name="_source"></a>SOURCE CODE <a href="#_top"><img alt="^" border="0" src="../../up.png"></a></h2>
<div class="fragment"><pre>0001 <a name="_sub0" href="#_subfunctions" class="code">function r = plus(p,q)</a>
0002 <span class="comment">% plus --- p+q is the join of p and q</span>
0003 
0004 n1 = <a href="nv.html" class="code" title="function n = nv(p)">nv</a>(p);
0005 n2 = <a href="nv.html" class="code" title="function n = nv(p)">nv</a>(q);
0006 
0007 <span class="keyword">if</span> n1 ~= n2
0008     error(<span class="string">'+ only defined for partitions on the same ground set'</span>);
0009 <span class="keyword">end</span>
0010 
0011 r = q;
0012 
0013 n = n1;
0014 
0015 <span class="keyword">for</span> i=1:n-1
0016     idx = find(p.array(:,i));
0017     irow = p.array(idx,:);
0018     <span class="keyword">for</span> j=find(irow)
0019         r=<a href="merge.html" class="code" title="function q = merge(p,x,y)">merge</a>(r,i,j);
0020     <span class="keyword">end</span>
0021 <span class="keyword">end</span>
0022 r.array = sortrows(r.array);</pre></div>
<hr><address>Generated on Fri 30-Apr-2010 07:51:16 by <strong><a href="http://www.artefact.tk/software/matlab/m2html/">m2html</a></strong> &copy; 2003</address>
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